How do they decide which Tuesday of the month is Mardi Gras?
Mardi Gras French for “Fat Tuesday” is the Tuesday before Ash Wednesday. Ash Wednesday, the start of Lent, is the Wednesday 46 days before Easter. Easter is celebrated on the first Sunday that occurs after the first full moon on or after the vernal equinox. The vernal equinox is always on March 21. Easter must be on a Sunday between March 22 and April 25.